Game.LambdaHack.Common.Point

Basic operations on 2D points represented as linear offsets.

Documentation

type X = Int

Spacial dimension for points and vectors.

type Y = Int

Spacial dimension for points and vectors.

data Point

2D points in cartesian representation. Coordinates grow to the right and down, so that the (0, 0) point is in the top-left corner of the screen. Coordinates are never negative.

Constructors

Point

Fields

px :: !X

py :: !Y

Instances

Enum Point

Eq Point

Ord Point

Read Point

Show Point

Generic Point

Binary Point

NFData Point

type Rep Point

dummyPoint :: Point

maxLevelDimExponent :: Int

The maximum number of bits for level X and Y dimension (16). The value is chosen to support architectures with 32-bit Ints.

chessDist :: Point -> Point -> Int

The distance between two points in the chessboard metric.

euclidDistSq :: Point -> Point -> Int

Squared euclidean distance between two points.

adjacent :: Point -> Point -> Bool

Checks whether two points are adjacent on the map (horizontally, vertically or diagonally).

inside :: Point -> (X, Y, X, Y) -> Bool

Checks that a point belongs to an area.

bla :: X -> Y -> Int -> Point -> Point -> Maybe [Point]

Bresenham's line algorithm generalized to arbitrary starting eps (eps value of 0 gives the standard BLA). Skips the source point and goes through the second point to the edge of the level. GIves Nothing if the points are equal. The target is given as Point to permit aiming out of the level, e.g., to get uniform distributions of directions for explosions close to the edge of the level.

fromTo :: Point -> Point -> [Point]

A list of all points on a straight vertical or straight horizontal line between two points. Fails if no such line exists.